1. Field of the Invention
The present invention relates to a lateral pipe lining material used for the rehabilitation of lateral pipes that branch from a main pipe, a lateral pipe lining material production method, and a lateral pipe lining method for rehabilitating lateral pipes using the lateral pipe lining material.
2. Description of the Related Art
When a lateral pipe that branches from a main pipe such as a water line or a sewage line that is buried in the earth wears out, methods are commonly used in which lateral pipes are repaired without excavating main pipes or lateral pipes (see JP 2006-123547A, for example).
With this method, a lateral pipe lining material having a flange at one end is installed inside a pressurization bag with the flange placed on the positioning nozzle of a work robot introduced into the main pipe. The work robot is driven to bring the flange of the lining into tight contact with the periphery of the lateral pipe opening of the main pipe. Compressed air is then supplied to the pressurization bag to insert the lateral pipe lining material into the lateral pipe towards the ground surface. The lateral pipe lining material is heated while being pressed onto the inner circumferential surface of the lateral pipe. After that, a thermosetting resin that is impregnated into the pipe lining material is cured. The lateral pipe is thus repaired by having its inner circumferential surface lined with the cured lateral pipe lining material.
This type of lateral pipe lining material is composed of a tubular flexible resin-absorbing material impregnated with a liquid curable resin, and the outer circumferential surface thereof (which becomes the inner circumferential surface when the pipe lining material is everted) is coated with a flexible tube composed of a plastic film that is highly impermeable to air. One end of the lateral pipe lining material is folded back, and the resin that is impregnated into the resin-absorbing material in this section is previously cured in the factory in order to provide a hard flange.
With this type of lateral pipe lining material, the tubular resin-absorbing material and flange are integrally formed, which is disadvantageous in that mass production is difficult. Therefore, JP 2000-37777A proposes a method for producing a lateral pipe lining material, in which the flange of the lateral pipe lining material and the resin-absorbing material thereof are produced separately and later bonded.
However, with the lateral pipe lining material of the type described in JP 2000-37777A, the end of the tubular resin-absorbing material is pressed outwards and widened on the flange of the lateral pipe lining material, and an additional flange is used to press the widened end of the tubular resin-absorbing material against the flange of the lateral liner for fixture therebetween. A problem is thus presented in that certain skill is required for fixing the flange members to the tubular resin-absorbing material, and also two flange members are disadvantageously required.